Using 5' rapid amplification of cDNA ends (5'RACE) techniques, the gene structure and transcription start sites for BLT1 and BLT2 were studied. Segments of the 5' promoter region have been cloned into reporter genes in order to characterize the promoter region. 5' deletion mutant reporter genes are being utilized to begin to understand those segments important in the control of basal expression of these genes in different cells and to understand the control of expression in response to a variety of pro and anti inflammatory stimuli.